Lifting jack



W. J. MELCHIOR Aug. 21, 192.3.

LIFTING JACK Filed Aug. 25, 1921 2 Sheets-Sheet 1 ATTORNEYS WITNESSIZAug. 21, 1923.

W. J. MELCHIOR LIFTING JACK Filed Aug. 25, 1921 2 Sheets-Sheet 2INVENTOH I k J/VEL, A /06 ATTORNEYS WIT/VESSE Patented Augzl, 1923.

hearse rates means Parana @FFHCE.

WILLIAM J. MELCH IOR, OF FARGO, NORTH DAKOTA.

LIFTIN G JACK.

Application flled August 25, 1921. serial No. 495,235.

and useful Improvements in Lifting Jacks,

of which the following is a specification.

This invention relates to a lifting jack and more particularly to alifting jack which is operable by compressed air.

The object of the invention is to provide a jack of the above characterwhich is portable and particularlyadapted for raising automobiles,vehicles or the like in a quick and positive manner.

It is also an important object of the invention that the liftingdistanceof the jack be considerably greater than that possible with the usualportable jack now commonly em loyed for the same purpose.

, ther objects and objects relating to details of construction,combination and arvrangement of parts will hereinafter appear in thedetail description to follow. J

The invention is illustrated by wayof example in the accompanyingdrawings, in

Figure 1 is a side elevation showing a' lifting jack constructed inaccordance with the present invention, and also showing the means forconnecting the same with a source of compressed air,

Figure 2 is a vertical central sectional view of the same.

Referring to the drawings more particularly, 10 indicates a cylinderwhich is vertically disposed and having formed therewith at its one enda base 11 adapted to form a closure for the lower end of the cylinder,as shown, at the other end of the cylinder there is formed a flange 12,the purpose of which will later be made apparent. Within the cylinder 10there is slidably positioned a 'hollow piston'13. The piston 13 isformed with an enlargement 14 adjacent its lower end and below theenlargement'there is positioned a packing ring 15 which is preferably ofleather or the like. The packing ring 15 is held in position by a washer16, said,

washer being secured to the piston bythe means of screws as indicated at17. The lower end of the piston is formed with a closure 18 which isheld in spaced relation with the base 11 by a set screw 19. As .isobvious by manipulating the 'set screw 19, the cham ber between the endclosure 18 of the piston 13 and the base 11 may be increased, ordecreased as desired. 3

.An annular plate member 20 encircles the top of the piston 13, saidplate member being secured to the flange 12 by the bolts 21.

The upper end of the piston 13 isinteriorly threaded and adapted toreceive the threaded plug 22. The plug 22 has passing centrallytherethrough the stem 23 which has threaded upon its lower, end thepiston head 24, as shown. The piston head 24 is adapted to slide withinthe hollow piston 13 and is formed with an ofiset portion as at 25,which is adapted to receive the packing ring 26, the packing ring beinpreferably of leather or a similar materiai l. The packing ring is heldin position by the washer 27, said washer being in turn secured to thepiston head 24 by the means of the screw 28. A set screw 28' is threadedinto the lower side of the face of the piston head 24 and bymanipulating the same the chamber existing between the piston head24'and the head closure 18 of the piston 13 may be decreased orincreased as desired.

The stem 23 is formedwith a bore 29 I which extends the entire lengththereof, said bore communicating in its lower endwith the orifice 30formed in the piston head 24. Theupper end of the bore is closed by aplug 31 and adjacent the upper end of the stem there is threaded-thereina nipple 32, said nipple carrying on its outer end a coupling 33; alsoupon the upper end of the stem 23 there is removably positioned a saddle34 which is adapted to engage beneath the axle of an automobile or othervehicle.

The cylinder 10 is formed with a handle 35 by which the lifting jack asa whole may be carried about. In the base 11 there is formed a passage36'which communicates in its one end with the interior of the cylinder10, and at its other end with a nipplev37. The nipple 37 carries acoupling member 38 to which there is connected a flexible hose 39, saidhose in turn communiconnected with a compressed air supply pipe 43; alsothere is connected with the T- fitting 41' a second two-way valye 44,said valve carrying a coupling 45 which connected with the one end of aflexible hose 46, the other end of the hose 46 being connected with thecoupling 33 carried by the nipple 32. The valve member 44 is alsoprovided with an eduction nipple 44' wh ch may be brought intocommunication with the flexible hose 46 by the manipulation of a theoperating handle of the valve 44.

In the operation of the present device, the jack is placed beneath theautomobile so that its saddlemay engage the axle thereof,

and when air is admitted through the valve 40 into the cylinder 10 andbeneath the piston 13, the piston 13 will be raised and the vehiclelifted. It may be observed that by properl manipulating the valve 40that the ve icle may be raised at different heights by the iston 13. Incase the piston 13 the spirit of my invention, as indicated by theappended claims.

I claim:

1. A pneumatic jack comprising an upright cy inder, a pair of telescopicpistons within said cylinder and upwardly movable with respect thereto,said cylinder having its lower end closed and forming a compression headfor the outermost piston and the last named piston forming a compressionhead for the innermost piston, means for normally maintaining each ofsald lstons in spaced relation with its associate compres sion head, atubular stem extending upwardly from the innermost piston carrying asaddle at its free end and communicating with the space beneath saidpiston at its inner end, a compressed fluidsupply pipe, a hose extensionbetween said supply pipe and the upper end of the tubular stem wherebycompressed fluid may be admitted beneath the innermost piston, and meanswhereby compressed fluid may be admitted beneath the outermost piston.

2. A pneumatic jack comprising an upright cylinder, a pair of telescopicpistons within said cylinder and upwardly movable with respect thereto,said cylinder having its lower end closed and forming a compression headfor the outermost piston and the last named piston forming a compressionhead for the innermost piston, means whereby the space existing betweeneach piston head and its associated compression head may be adjusted andthereby to regulate the height of the pneumatic jack, and

means whereby compressed fluid may be introduced beneath each of thepiston, heads for raising the same.

3. A pneumatic jack comprising an upright cylinder a pair of telescopicpistons within said cy inder and upwardly movable with respect thereto,said cylinder-having its lower end closed and forming a compression headfor the outermost piston and the last named piston forming a compressionhead for the innermost piston, set screws carried by each piston headadapted to be used for adjusting the space existing between each pistonhead and its associated compression head, and means whereby compressedfluid may be admitted beneath each piston for elevating the same. e

' WILLIAM J. MELCHIOR.

